Lifeboat Foundation

Neutron star mergers are a treasure trove for new physics signals, with implications for determining the true nature of dark matter, according to research from Washington University in St. Louis.

On Aug. 17, 2017, the Laser Interferometer Gravitational-wave Observatory (LIGO), in the United States, and Virgo, a detector in Italy, detected gravitational waves from the collision of two neutron stars. For the first time, this astronomical event was not only heard in gravitational waves but also seen in light by dozens of telescopes on the ground and in space.

Physicist Bhupal Dev in Arts & Sciences used observations from this neutron star merger — an event identified in astronomical circles as GW170817 — to derive new constraints on axion-like particles. These hypothetical particles have not been directly observed, but they appear in many extensions of the standard model of physics.

A team of scientists has successfully mimicked black hole conditions by creating a quantum vortex in superfluid helium, shedding light on gravitational interactions and quantum field theories in curved spacetimes.

Scientists have for the first time created a giant quantum vortex to mimic a black hole in superfluid helium that has allowed them to see in greater detail how analog black holes behave and interact with their surroundings.

Research led by the University of Nottingham, in collaboration with King’s College London and Newcastle University, has created a novel experimental platform: a quantum tornado. They have created a giant swirling vortex within superfluid helium that is chilled to the lowest possible temperatures. Through the observation of minute wave dynamics on the superfluid’s surface, the research team has shown that these quantum tornados mimic gravitational conditions near rotating black holes. The research has been published today in Nature.

When it comes to the cosmic conundrum of how early galaxies grew to become so massive so quickly Gz9p3 could be a real puzzle. Not only is it more massive than expected, but it is around 10 times more massive than other galaxies the JWST has seen in similar eras of the universe’s history.

Related: James Webb Space Telescope complicates expanding universe paradox by checking Hubble’s work

“Just a couple of years ago, Gz9p3 appeared as a single point of light through the Hubble Space Telescope,” Kit Boyett, team member and a scientist at the University of Melbourne, wrote for the institute’s Pursuit publication. “But by using the JWST we could observe this object as it was 510 million years after the Big Bang, around 13 billion years ago.”

It is with sadness — and deep appreciation of my friend and colleague — that I must report the passing of Vernor Vinge.

The technological singularity —or simply the singularity^[1] —is a hypothetical future point in time at which technological growth becomes uncontrollable and irreversible, resulting in unforeseeable consequences for human civilization.^[2][3] According to the most popular version of the singularity hypothesis, I. J. Good’s intelligence explosion model, an upgradable intelligent agent will eventually enter a “runaway reaction” of self-improvement cycles, each new and more intelligent generation appearing more and more rapidly, causing an “explosion” in intelligence and resulting in a powerful superintelligence that qualitatively far surpasses all human intelligence.^[4]

Continue reading “Technological singularity” »

Everyone loves a two-for-one deal—even physicists looking to tackle unanswered questions about the cosmos. Now, scientists at the Department of Energy’s SLAC National Accelerator Laboratory are getting just such a twofer: Particle detectors originally developed to look for dark matter are now in a position to be included aboard the Line Emission Mapper (LEM), a space-based X-ray probe mission proposed for the 2030s.

We don’t live in a universe where matter floats around in empty space… we live in a universe of energy fields that spread throughout the universe and interact with one another, creating everything we see in the process.

The new map, dubbed Quaia, includes around 1,295,502 quasars from across the visible Universe and could help astronomers better understand the properties of dark matter.

Think the Upside Down in Stranger Things is a work of fiction? Well, it is, but something eerily reminiscent of the Upside Down – dark matter, or a “dark mirror” universe – is being studied and taken very seriously by scientists.

So what exactly is dark matter? NASA explains, Like ordinary matter, dark matter takes up space and holds mass. But it doesn’t reflect, absorb, or radiate light – at least not enough for us to detect yet.

In Verlinde’s picture of emergent gravity, as soon as you enter low-density regions — basically, anything outside the solar system — gravity behaves differently than we would expect from Einstein’s theory of general relativity. At large scales, there is a natural inward pull to space itself, which forces matter to clump up more tightly than it otherwise would.

This idea was exciting because it allowed astronomers to find a way to test this new theory. Observers could take this new theory of gravity and put it in models of galaxy structure and evolution to find differences between it and models of dark matter.

Over the years, however, the experimental results have been mixed. Some early tests favored emergent gravity over dark matter when it came to the rotation rates of stars. But more recent observations haven’t found an advantage. And dark matter can also explain much more than galaxy rotation rates; tests within galaxy clusters have found emergent gravity coming up short.